Subject: [PATCH v2 net-next] drivers/net/bonding: User strscpy() to copy device name

From: David Laight <[email-masked]>
Date: Mon, 8 Jun 2026 22:30:42 +0100

Replace the potentially unbounded strcpy() with the safer strscpy().

Signed-off-by: David Laight <[email-masked]>
---

v2: Merge the patches for bond_main.c and bond_options together.

This is one of a group of patches that remove potentially unbounded
strcpy() calls.

They are mostly replaced by strscpy() or, when strlen() has just been
called, with memcpy() (usually including the '\0').

Calls with copy string literals into arrays are left unchanged.
They are safe and easily detected as such.

The changes were made by getting the compiler to detect the calls and
then fixing the code by hand.

Note that all the changes are only compile tested.

Some Makefiles were changed to allow files to contain strcpy().
As well as 'difficult to fix' files, this included 'show' functions
as they really need to use sysfs_emit() or seq_printf().

All the patches are being sent individually to avoid very long cc lists.
Apologies for the terse commit messages and likely unexpected tags.
(There are about 100 patches in total.)

 drivers/net/bonding/bond_main.c    | 2 +-
 drivers/net/bonding/bond_options.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletion.(-)

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index af82a3df2c5d..76ca61cad875 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -1792,7 +1792,7 @@ static void bond_fill_ifbond(struct bonding *bond, struct ifbond *info)
 
 static void bond_fill_ifslave(struct slave *slave, struct ifslave *info)
 {
-	strcpy(info->slave_name, slave->dev->name);
+	strscpy(info->slave_name, slave->dev->name);
 	info->link = slave->link;
 	info->state = bond_slave_state(slave);
 	info->link_failure_count = slave->link_failure_count;
diff --git a/drivers/net/bonding/bond_options.c b/drivers/net/bonding/bond_options.c
index 7380cc4ee75a..c57b7d6af043 100644
--- a/drivers/net/bonding/bond_options.c
+++ b/drivers/net/bonding/bond_options.c
@@ -1525,7 +1525,7 @@ static int bond_option_primary_set(struct bonding *bond,
                if (strncmp(slave->dev->name, primary, IFNAMSIZ) == 0) {
                        slave_dbg(bond->dev, slave->dev, "Setting as primary slave\n");
                        rcu_assign_pointer(bond->primary_slave, slave);
-                       strcpy(bond->params.primary, slave->dev->name);
+                       strscpy(bond->params.primary, slave->dev->name);
                        bond->force_primary = true;
                        bond_select_active_slave(bond);
                        goto out;
--
2.39.5